summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/entry.S
Commit message (Collapse)AuthorAgeFilesLines
* MIPS: Fix IRQ tracing & lockdep when reschedulingPaul Burton2017-07-051-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d8550860d910c6b7b70f830f59003b33daaa52c9 upstream. When the scheduler sets TIF_NEED_RESCHED & we call into the scheduler from arch/mips/kernel/entry.S we disable interrupts. This is true regardless of whether we reach work_resched from syscall_exit_work, resume_userspace or by looping after calling schedule(). Although we disable interrupts in these paths we don't call trace_hardirqs_off() before calling into C code which may acquire locks, and we therefore leave lockdep with an inconsistent view of whether interrupts are disabled or not when CONFIG_PROVE_LOCKING & CONFIG_DEBUG_LOCKDEP are both enabled. Without tracing this interrupt state lockdep will print warnings such as the following once a task returns from a syscall via syscall_exit_partial with TIF_NEED_RESCHED set: [ 49.927678] ------------[ cut here ]------------ [ 49.934445] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3687 check_flags.part.41+0x1dc/0x1e8 [ 49.946031] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) [ 49.946355] CPU: 0 PID: 1 Comm: init Not tainted 4.10.0-00439-gc9fd5d362289-dirty #197 [ 49.963505] Stack : 0000000000000000 ffffffff81bb5d6a 0000000000000006 ffffffff801ce9c4 [ 49.974431] 0000000000000000 0000000000000000 0000000000000000 000000000000004a [ 49.985300] ffffffff80b7e487 ffffffff80a24498 a8000000ff160000 ffffffff80ede8b8 [ 49.996194] 0000000000000001 0000000000000000 0000000000000000 0000000077c8030c [ 50.007063] 000000007fd8a510 ffffffff801cd45c 0000000000000000 a8000000ff127c88 [ 50.017945] 0000000000000000 ffffffff801cf928 0000000000000001 ffffffff80a24498 [ 50.028827] 0000000000000000 0000000000000001 0000000000000000 0000000000000000 [ 50.039688] 0000000000000000 a8000000ff127bd0 0000000000000000 ffffffff805509bc [ 50.050575] 00000000140084e0 0000000000000000 0000000000000000 0000000000040a00 [ 50.061448] 0000000000000000 ffffffff8010e1b0 0000000000000000 ffffffff805509bc [ 50.072327] ... [ 50.076087] Call Trace: [ 50.079869] [<ffffffff8010e1b0>] show_stack+0x80/0xa8 [ 50.086577] [<ffffffff805509bc>] dump_stack+0x10c/0x190 [ 50.093498] [<ffffffff8015dde0>] __warn+0xf0/0x108 [ 50.099889] [<ffffffff8015de34>] warn_slowpath_fmt+0x3c/0x48 [ 50.107241] [<ffffffff801c15b4>] check_flags.part.41+0x1dc/0x1e8 [ 50.114961] [<ffffffff801c239c>] lock_is_held_type+0x8c/0xb0 [ 50.122291] [<ffffffff809461b8>] __schedule+0x8c0/0x10f8 [ 50.129221] [<ffffffff80946a60>] schedule+0x30/0x98 [ 50.135659] [<ffffffff80106278>] work_resched+0x8/0x34 [ 50.142397] ---[ end trace 0cb4f6ef5b99fe21 ]--- [ 50.148405] possible reason: unannotated irqs-off. [ 50.154600] irq event stamp: 400463 [ 50.159566] hardirqs last enabled at (400463): [<ffffffff8094edc8>] _raw_spin_unlock_irqrestore+0x40/0xa8 [ 50.171981] hardirqs last disabled at (400462): [<ffffffff8094eb98>] _raw_spin_lock_irqsave+0x30/0xb0 [ 50.183897] softirqs last enabled at (400450): [<ffffffff8016580c>] __do_softirq+0x4ac/0x6a8 [ 50.195015] softirqs last disabled at (400425): [<ffffffff80165e78>] irq_exit+0x110/0x128 Fix this by using the TRACE_IRQS_OFF macro to call trace_hardirqs_off() when CONFIG_TRACE_IRQFLAGS is enabled. This is done before invoking schedule() following the work_resched label because: 1) Interrupts are disabled regardless of the path we take to reach work_resched() & schedule(). 2) Performing the tracing here avoids the need to do it in paths which disable interrupts but don't call out to C code before hitting a path which uses the RESTORE_SOME macro that will call trace_hardirqs_on() or trace_hardirqs_off() as appropriate. We call trace_hardirqs_on() using the TRACE_IRQS_ON macro before calling syscall_trace_leave() for similar reasons, ensuring that lockdep has a consistent view of state after we re-enable interrupts. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15385/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* MIPS: kernel: entry.S: Set correct ISA level for mips_ihbMarkos Chandras2015-05-171-1/+2
| | | | | | | | | | | | | | | | [ Upstream commit aebac99384f7a6d83a3dcd42bf2481eed2670083 ] Commit 6ebb496ffc7e("MIPS: kernel: entry.S: Add MIPS R6 related definitions") added the MIPSR6 definition but it did not update the ISA level of the actual assembly code so a pre-MIPSR6 jr.hb instruction was generated instead. Fix this by using the MISP_ISA_LEVEL_RAW macro. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Fixes: 6ebb496ffc7e("MIPS: kernel: entry.S: Add MIPS R6 related definitions") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9386/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
* MIPS: MT: Remove SMTC supportRalf Baechle2014-05-241-38/+0
| | | | | | | | | | | | | | | Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras <Markos.Chandras@imgtec.com> patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-12-121-0/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull big execve/kernel_thread/fork unification series from Al Viro: "All architectures are converted to new model. Quite a bit of that stuff is actually shared with architecture trees; in such cases it's literally shared branch pulled by both, not a cherry-pick. A lot of ugliness and black magic is gone (-3KLoC total in this one): - kernel_thread()/kernel_execve()/sys_execve() redesign. We don't do syscalls from kernel anymore for either kernel_thread() or kernel_execve(): kernel_thread() is essentially clone(2) with callback run before we return to userland, the callbacks either never return or do successful do_execve() before returning. kernel_execve() is a wrapper for do_execve() - it doesn't need to do transition to user mode anymore. As a result kernel_thread() and kernel_execve() are arch-independent now - they live in kernel/fork.c and fs/exec.c resp. sys_execve() is also in fs/exec.c and it's completely architecture-independent. - daemonize() is gone, along with its parts in fs/*.c - struct pt_regs * is no longer passed to do_fork/copy_process/ copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump. - sys_fork()/sys_vfork()/sys_clone() unified; some architectures still need wrappers (ones with callee-saved registers not saved in pt_regs on syscall entry), but the main part of those suckers is in kernel/fork.c now." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits) do_coredump(): get rid of pt_regs argument print_fatal_signal(): get rid of pt_regs argument ptrace_signal(): get rid of unused arguments get rid of ptrace_signal_deliver() arguments new helper: signal_pt_regs() unify default ptrace_signal_deliver flagday: kill pt_regs argument of do_fork() death to idle_regs() don't pass regs to copy_process() flagday: don't pass regs to copy_thread() bfin: switch to generic vfork, get rid of pointless wrappers xtensa: switch to generic clone() openrisc: switch to use of generic fork and clone unicore32: switch to generic clone(2) score: switch to generic fork/vfork/clone c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone() take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h mn10300: switch to generic fork/vfork/clone h8300: switch to generic fork/vfork/clone tile: switch to generic clone() ... Conflicts: arch/microblaze/include/asm/Kbuild
| * mips: switch to saner kernel_execve() semanticsAl Viro2012-10-151-11/+1
| | | | | | | | | | Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * MIPS: Switch over to generic sys_execve and kernel_execve.Ralf Baechle2012-10-141-0/+9
| | | | | | | | | | | | | | | | This version contains a few updates by David Daney, in particular it's now using __builtin_frame_address() instead of asm() which depending on personal taste, is slightly more appealing. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * mips: switch to generic kernel_thread()Al Viro2012-10-141-0/+7
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | MIPS: Fix endless loop when processing signals for kernel tasksDmitry Adamushko2012-12-051-1/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem occurs [1] when a kernel-mode task returns from a system call with a pending signal. A real-life scenario is a child of 'khelper' returning from a failed kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ]. kernel_execve() fails due to a pending SIGKILL, which is the result of "kill -9 -1" (at least, busybox's init does it upon reboot). The loop is as follows: * syscall_exit_work: - work_pending: // start_of_the_loop - work_notifysig: - do_notify_resume() - do_signal() - if (!user_mode(regs)) return; - resume_userspace // TIF_SIGPENDING is still set - work_pending // so we call work_pending => goto // start_of_the_loop More information can be found in another LKML thread: http://www.serverphorums.com/read.php?12,457826 [1] The problem was also reproduced on !CONFIG_VM86 x86, and the following fix was accepted. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=29a2e2836ff9ea65a603c89df217f4198973a74f Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3571/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Merge the identical "return from syscall" per-ABI codeAl Viro2012-09-221-3/+9
| | | | | | | | No need to keep 4 copies of that stuff; merged and taken to entry.S, unused public symbols there killed off. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Prevent hitting do_notify_resume() with !user_mode(regs).Al Viro2012-09-221-0/+3
| | | | | | | Too late to do anything there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Split do_syscall_trace into two functions.Ralf Baechle2011-05-191-3/+2
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Use single define for pending work on syscall exitRalf Baechle2011-05-191-1/+1
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] SMTC: Close tiny holes in the SMTC IPI replay system.Kevin D. Kissell2008-10-031-5/+5
| | | | | Signed-off-by: Kevin D. Kissell <kevink@paralogos.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] SMTC: Interrupt mask backstop hackKevin D. Kissell2007-07-121-0/+2
| | | | | | | | | | | To support multiple TC microthreads acting as "CPUs" within a VPE, VPE-wide interrupt mask bits must be specially manipulated during interrupt handling. To support legacy drivers and interrupt controller management code, SMTC has a "backstop" to track and if necessary restore the interrupt mask. This has some performance impact on interrupt service overhead. Disable it only if you know what you are doing. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] lockdep: Handle interrupts in R3000 style c0_status register.Chris Dearman2007-03-291-1/+5
| | | | | | | | Check the IEP bit for R3000 style processors when checking to see if interrupts will be reenabled in restore_all. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Make entry.S a little more readable.Franck Bui-Huu2007-02-131-11/+8
| | | | | | | | | | When CONFIG_PREEMPT is not set, it also moves one branch instruction from ret_from_irq() to ret_from_exception(). Therefore we favour the return from irq case which should be more common than the other one. Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com> Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] SMTC: Fix crash if # of TC's > # of VPE's after pt_regs irq cleanup.Ralf Baechle2006-11-011-0/+3
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] ret_from_irq adjustmentAtsushi Nemoto2006-10-091-5/+9
| | | | | | | | | | | Make sure that RA on top of interrupt stack is an address of ret_from_irq, so that dump_stack etc. can trace info interrupted context. Also this patch fixes except_vec_vi_handler and __smtc_ipi_vector which seems broken. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Complete fixes after removal of pt_regs argument to int handlers.Ralf Baechle2006-10-081-1/+0
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] TRACE_IRQFLAGS_SUPPORT support.Ralf Baechle2006-07-131-0/+15
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [PATCH] sched: cleanup, remove task_t, convert to struct task_structIngo Molnar2006-07-031-1/+1
| | | | | | | | | | | | cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-301-1/+0
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [MIPS] Fix use of ehb instruction for non-R2 configurations.Ralf Baechle2006-06-291-3/+3
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Fix typoRalf Baechle2006-06-011-1/+1
| | | | | | Found by Chris Dearman (chris@mips.com). Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] MT: Improved multithreading support.Ralf Baechle2006-04-191-0/+34
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] R2: Instruction hazard barrier.Ralf Baechle2006-04-191-0/+15
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Rewrite spurious_interrupt from assembler to C.Ralf Baechle2006-04-191-26/+0
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Fix excessive signal latencies.Ralf Baechle2005-10-291-1/+1
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Fix preemption bug.Ralf Baechle2005-10-291-2/+1
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Use preempt_schedule_irq.Ralf Baechle2005-10-291-5/+2
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Remove unused arguments from preempt_{start,stop}/local_irq_{en,dis}able.Thiemo Seufer2005-10-291-18/+17
| | | | | | | | Don't clobber the preloaded TI_FLAGS in a2 needlessly. Unexport local functions. Signed-off-by: Thiemo Seufer <ths@networkno.de> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* De-optimize and decomplicate the spurious interrupt handler.Thiemo Seufer2005-10-291-8/+5
| | | | | Signed-off-by: Thiemo Seufer <ths@networkno.de> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+155
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-25 02:56:06 +0000